Fluorinated oxo-compounds



United States Patent Ofice 3,410,853 Patented Nov. 12, 1968 3,410,853 FLUORINATED OXO-COMPOUNDS Robert J. Koshar, Lincoln Township, Washington County,

Minn., assignor to Minnesota Mining and Manufacturing Company, St. Paul, Minn., a corporation of Delaware No Drawing. Filed Mar. 15, 1963, Ser. No. 267,381 6 Claims. (Cl. 260248) This invention relates to new and novel fiuorinated carbonyl compounds and particularly to fluorinated ureas and carbamyl fluorides and to processes by which they are obtained.

It is well known that fluoride is the most electronegative element and therefore is an oxidizing agent with very high potential. However, fluorine is a very low boiling and highly corrosive gas requiring rather special techniques in its manipulations, which limits the extent to which its high oxidizing potential could otherwise be utilzed for use where high output is required. Among such possible uses are a number of industrial processes where high oxidizing potential can extend the range of application, increase rate of output and the like. Many industrial requirements have heretofore been met in a more or less satisfactory way using less powerful and more readily handled oxidizing agents. Bleaching of wood pulp, fabrics, flour and such materials may be mentioned among such uses. However, more active oxidizing agents would be advantageous in such industrial uses if readily handled, permitting shorter process time, use of lower concentration, etc. Another zfield in which very high oxidation potentials are particularly desirable is in the field of reactiontype propellants where extreme releases of energy are necessary to achieve high specific impulses. For such purposes the availability of relatively safely handled material possessing even a substantial fraction of the oxidizing capacity of fluorine but still at a high potential would be very desirable in formulating solid propellants, or for use as oxidizers in liquid propellent systems.

It is known that the oxidizing potential of fluorine is retained to a considerable extent in -NF and =NF radicals. In previously disclosed processes, the fiuorination of carbon-nitrogen compounds having at least one carbon directly bonded to 3 nitrogen atoms directly with elemental fluorine is shown to produce compounds containing a plurality of NF and =NF groups. Thus, the predominant compounds formed from ammeline by fluorination with elemental fluorine have been found to be bis(difluoramino)difluoromethane, tris(di-fluoramino) fluoromethane, perfluoroformamidine rand perfluoroguanidine.

The above described compounds formed from ammeline are formed, insofar as can be determined, by fluorinolytic elimination of CO from the ring followed by greater or less fluorinolysis of the remaining bonds of the ammeline structure and replacement of hydrogen atoms by fluorine. Thus the above compounds are devoid of oxygen and hydrogen.

We have now found that acyclic and cyclic oxygencontaining products of the reaction are present among the higher boiling less volatile fractions from the fluorination of ammeline, imidurazole and cyameluric acid and like tautomerizable ketoenol group-containing polynitrogen heterocycles under certain conditions and then constitute a substantial portion of the products.

It is an object of this invention to provide fluorine-containing compounds of C, N and having substantial oxidizing capacity. A further object is to provide highly fluorinated oxo-compounds containing fluorine in oxidizing configurations. A still further object is to provide oxidants having high oxidizing capacity at a high potential. Another object of the invention is to provide 'a process for producing the compositions of the invention. Other objects will become evident hereinafter.

In accordance with the above and other objects of this invention, it has now been found that direct fiuorination of ammeline with elemental fluorine also proceeds without elimination of the carbonyl group to give fluorinated carbonyl oxo-compounds having the formula wherein R' is a member of the group consisting of F and NPR"; R and R" are individually selected from the group consisting of and (F N)- -CF NFCF(NF so that the molecule contains from 2 to 3 carbon atoms arid no more than 5 nitrogen atoms and R and R taken together, thus forming heterocyclic ring-containing compounds, are selected from the group consisting of In addition to the above groups, R and R" can also be the fluorimino substituted groups:

II II CFz-NF-O-NF-C-NFz and Name Structure Name Structure These compounds are oxidizing agents in varying degree and particularly when they contain difluoramino groups are powerful oxidants of value for rocketry. They are quite shock-sensitive and can be detonated. They have boiling points in the approximate range of to about 125 C. The compounds ofthe invention are further chemically reactive and are hydrolyzed, for example, by dilute sulfuric acid in accordance with the equation:

F o F F F RI I( il IR H1O C02 R1\IH R"I IH The monofluoramines wherein the R or R" comprises at least one carbon atom are also valuable materials. The following table sets forth exemplary rnonofluoramines formed by hydrolysis of compounds of the invention shown in the following table:

Name Structure Exemplary compounds of the invention wherein R is F include the carbamyl fluorides shown in the following table:

Perfluorodiaminomethylcarbamyl (FzN) 2C F-N F-C-F These carbamyl fluorides are hydrolyzed by water to yield the monofluoramines noted above thus:

It will be noted that in fluorinated imines or imino compounds the carbon-nitrogen double bond is intact although empirically the compound is named as perfluorinated. The significance of the content of fluorine to nitrogen bonds is that such bonds possess energy and are powerful oxidants. It is rather unexpected that direct fluorination reactions result in useful and stable products with high contents of nitrogen to fluorine bonds still containing a carbonyl group.

Thus, it is found that direct fiuorination of ammeline and cyameluric acid using elemental fluorine replaces substantially all of the hydrogen atoms by fluorine atoms, whether these compounds are present undiluted or as a suspension in a suitable liquid inert to fluorine. Particularly under the conditions hereinafter described the carbonyl group is retained. It appears from what can be determined from the stoichiometry of the reaction and the analytical values obtained on the products that the reaction not only replaces substantially all of the hydrogen atoms by fluorine atoms but that in addition greater or lesser amounts of fluorine combine by addition to the carbon-nitrogen double bonds which are present. Addition of fluorine also causes some cleavage of the C-N skeletal chain of the polycyclic and inonocyclic substances. The resultant products, which vary over certain ranges of fluorine content, contain a number of compounds which can be isolated by the methods described herein. There is reason to believe that not all of the double bonds present add fluorine because complete fluorinolysis would be expected to result in complete decomposition of the source materials to produce CF COF and HF. Surprisingly, the reaction stops well short of complete degradation to produce white to yellowish liquids, which may be low-boiling, in which the fluorine content on analysis may vary from about 40 percent to about 65 percent by weight and the oxidizing capacity is up to about or more milliequivalents of iodine per gram. Oxidizing capacity is determined using excess potassium iodide in aqueous acetonitrile or acetic acid followed by titration with standard solutions of sodium thiosulfate. The products have vapor pressures up to about 50 mm. of Hg at 78 C. to less than 25 mm. of Hg at 25 C. The compositions of the invention are shocksensitive, but are usually not so sensitive that they cannot be handled conveniently.

There is a wide range of sensitivity among compounds which are sensitive to shock or impact. Many such compounds, although sensitive, can be used safely; commercial exposives fall in this class. A widely-used method of evaluating the degree of sensitivity consists of dropping a weight (frequently a two kilogram weight is employed) onto a small sample of the compound and determining the height of drop at which detonation occurs. The product of the weight used and height of drop, expressed in kg. cm., is then a measure of the sensitivity and this product is greater for the less sensitive materials.

The materials herein described have sensitivities, expressed as kg. cm., which place them outside the range of the most sensitive materials. The term shock-sensitive is employed herein to emphasize the high energy content of these compounds and the necessity for employing care in the manipulation of these compounds and not as an indication that these compounds are non-manipulable. They can be manipulated using suitable precautions, and thus they are different from many known materials having high oxidative capacity which cannot safely be manipulated. It is, of course, only normally prudent to exercise considerable care under all circumstances since, when detonated, materials ofsuch high energy content produce very violent explosions and in fact are so powerful as oxidizing agents that they can ignite many common organic substances. Care should be exercised in detonating even small quantities of these compositions for testing.

The compositions of the invention are thus seen -to be fluid, shock-sensitive compositions which contain carbon, nitrogen, oxygen and fluorine, and which have an oxidizing capacity of up to about 50 or more milliequivalents of iodine per gram. They are compounds with somewhat different physical properties, and can be separated from each other. They contain little or no residual hydrogen in the molecule. The com-positions of the invention are soluble in such solvents as methylene chloride, fluorotrichloromethane and the like. Certain of the compositions may be distilled with great caution under highly reduced pressure; others may be distilled readily at atmospheric pressure. They are also separated and can be characterized by vapor phase chromatography, employing a fluorochemical stationary phase as more fully described hereinafter. They are generally relatively soluble in fluorocarbon solvents such as perfluoro octane and higher boiling products of the reaction and are much less soluble in hydrocarbons. Their reactivity is variable.

When mixed with substances which can be oxidized, such as an organic polymer, and ignited as by means of a squib, they burn with intense heat and the formation of large volumes of gases. When treated with water, or exposed to moisture, these fiuorinated compounds may hydrolyze to a greater or less extent with a lowering or loss of their oxidizing power.

Broadly speaking, the process of the invention is carried out by treating ammeline, cyameluric acid or imidurazole with elemental fluorine. For best results, the starting material should be substantially anhydrous, to avoid destruction of the =NF or NF groups after their formation, and should be diluted with an inert solid diluent, e.'g., sodium fluoride. The processes can be carried out at a temperature in the range of about -100 to +60 C. or even somewhat higher. Reaction takes place very slowly at 100 C. and is markedly increased by raising the temperature to 75 or higher. It is preferred that ammeline be reacted to about 0 C. and cyameluric acid at about 25 C. Other compounds containing the ureido group or its tautomeric form may also be used, e.g. ammelide.

The fluorine is conveniently introduced under slight positive pressure, or if closed vessels are used, by employing diluents and proper precautions, pressures up to 100 psi. can be used. Preferably, the fluorine is diluted with nitrogen or other inert gas, such as argon, helium, a Freon, such as dichlorodifluoromethane, and the like, to give about 0.1 to 60 percent of fluorine in the gas stream. Too high a concentration is indicated by burning of the starting material and this can be avoided by reduction of the fluorine concentration and/or lowering the reaction temperatures, however, undiluted fluorine can be used, using great caution and slow addition when working with solid, finely powdered undiluted ammeline, Residual fluorine should always be flushed out of the reactants and the apparatus, using dry nitrogen or the like,

to avoid unpleasant and toxic exposure to fluorine as well as untoward effects owing to the strong oxidizing power of this substance. The apparatus used is preferably constructed from Monel metal or copper. The solid, finely divided ammeline is placed in a suitable container, such as a boat, which may be of stainless steel or copper or spread on a sheet or plate, and is then contacted with fluorine for a period ranging from about 10 minutes to about 8 hours.

Particularly effective fluorination with retention of CO groups results from passing the fluorine stream upwardly through a mixture of cyclic organic compound and sodium fluoride retained on a porous plate, e.g. sintered stainless steel. Another very effective method, which is adapted to operation on a relatively large scale or for continuous addition of the cyclic reactant, is to place the mixture or organic compound alone in a rotating drum through which the fluorine stream flows slowly. In this method mechanical design of the drum and angle of inclination can be used to alter the in-process-time in a continuous operation.

The longer times of contact are usually used with more highly diluted fluorine and for large samples in batch operations. Generally speaking, once the process has gone to completion, no further fluorine reacts, so that continuation of the flow of fluorine or time of contact is not deleterious; however, excessive exposure of fluorine, of the order of 10 hours or more when highly concentrated fluorine is used, should be avoided to suppress the possibility of extensive fluorinolysis. Preferably, the reaction mixture is maintained at a temperature in the range of about -20 to +25 C. and the fluorination process may be continued for about 5 hours or longer for larger samples in batch operations. The time depends on the fluorine flow rate as well as sample size. When convenient, lower temperatures can be used and it is preferred to use temperatures not in excess of about 50 C. for best results, the reactant is mixed with from 1 to 4 times its weight of finely divided sodium fluoride. Hydrogen fluoride formed in the reaction is taken up by the sodium fluoride in the reaction mixture and need not be removed subsequently from the products in a scrubber. The fluorine gas is passed over or through the solid mixture and the more volatile products including the bulk of the compounds of this invention as well as smaller fragments are condensed in a suitable trap cooled by liquid air or other means. The products of the process are recovered from excess fluorine and any highly volatile fiuorinated cleavage products such as CR NF etc. which may be present.

The following examples will more specifically illustrate the fiuorinated oxidant compounds of the invention and the process for their preparation. In these examples parts are by weight unless otherwise described and temperatures are in degrees centigrade.

Example 1 In a 2" x 10" copper tray are placed 3 grams of a dry mixture of equal parts of ammeline and sodium fluoride and the tray is placed in a 1.6 liter horizontal cylindrical copper reactor (3" dia.), having a polytetrafluoroethylene rupture disc at the top, inlet and outlet at the ends. The reactor and a cooling coil are immersed in a bath of perfluoro octane (mixed isomers). Cold ethanol is circulated through the coil so that the temperature of the bagl: -15 C. and that within the reactor is about A stream of dry prepurified nitrogen is passed through the reactor containing the sample at about 200 ml. per minute to flush out air because the fluorine subsequently introduced may produce explosives with oxygen. Fluorine (commercially available, pure) is introduced into the nitrogen stream (using Monel fittings) to give a concentration of about 5.7% by volume fluorine and the stream of nitrogen and fluorine is passed over the mixture in the reactor at about 5 C. for 1.5 hours. The

fluorine concentration is raised to 10.7% by volume and the stream is continued for 4.0 hours. A total of 0.11 mole of fluorine is used in all. The volatile and entrained fluorination products are removed at the far end of the reactor, passed through sodium fluoride in an iron tube maintained at about 25 (to remove hydrogen fluoride) and the residual materials are condensed in a borosilicate glass trap cooled in a liquid air bath. At the end of the reaction the flow of fluorine is stopped and that of nitrogen continued for about two hours to flush through resid- 10 ual amounts of fluorine and products. During this process the reactor is allowed to warm up to ambient room temperature. The copper tray contains 2.3 grams of solids including NaF and some HP.

The liquid in the trap (designated as A) is separated into fractions by connecting the trap (kept cold in liquid air) to a line passing serially through two receivers herein designated B and C. The first receiver, B, is cooled to 78 C. by carbon dioxide-trichloroethylene bath and the second receiver, C, is cooled in liquid air. The liquid air bath surrounding the original trap, A, is removed and the contents permitted to vaporize as the temperature gradually rises to ambient temperature. A liquid residue remains in the original trap (A). The less volatile portion of the vapors is condensed in receiver B, the more volatile material in receiver C. The product in C contains fragments such as CF NF and is discarded. Both compositions in B and in the original trap, A, are mixtures, part of the more volatile components being retained in trap A as a result of solubility in the less volatile constituents of that composition. The product distribution in trap A and receiver B can vary considerably depending on the time during which trap A is maintained at the ambient room temperature.

The product in the receiver (B) amounts to about 1.5 3 grams and contains at least twelve components which can be isolated by vapor phase chromatography employing a column composed of about 25% by weight of perfluoropolytributylamine (available from the Minnesota Mining and Manufacturing Company) on Celite at 25 C. Some of the compounds which are isolated include bis(difluoramino) difluoromethane, tris difluoramino fluoromethane, perfluoroguanidine, perfluoroformamidine in the ratio of about 3:1:1:1 as well as perfluoro(N-methylguanidine) [CF3NFC=NF] l l' l and his difluoramino fluorotrifluoromethylaminomethand [CF NFCF(NF )2].

About 0.8 ml. of a yellow liquid in contact with 130 ml. of vapor at about 140 mm. Hg at 25 C. remains in trap (A). It is characterized by infrared absorption in the 7.5 to 8.5a region (CF bonds), the 5.9 to 6.1, region (ascribed to the group C NF), the 10-11 region (=NF and NF groups) and absorptions at about 5 .411. ascribed to the carbonyl of the group:

tinuous phase on Celite at C. and is found to contain at least 11 components including:

Perfluoro (N-diaminomethylguanidine) (NFz) 2C FN F C=NF Perfluoro(N-diaminomethyl-triamino- (NF2)2CFNF C F(NF methane).

minomethylurea.

i Perfluoro (lamino-i-oxohexahydro- N F NF C FzN F 0 FN F2 1,3,5-triazine).

in the approximate ratio of 30:20:20z1.

Peak 1p Assignment Approx. Area Ratio -20 .5 NFg 2 +71 .5 NF 1 1 +99 CFz 2 +133 CF 1 i 1 Doublet.

The mass spectrum fragmentation pattern for perfluoro N-aminomethyl-N-diaminomethylurea exhibits numerous cationic species containing oxygen as well as other mass fragments which are consistent with the structure of this compound, including such higher mass cations as C N F O' C N F O and C N F O+. Its infrared spectrum shows absorption at 5.45 due to the canbonyl as well as absorptions at 7 .78.5,u. (CF region) and absorptions at 10.4,LL, 10.641. and 11.0,. (:NP and NF groups).

Perfluoro N-aminomethyl-N'-diaminomethylurea has a vapor pressure of about 14 mm. Hg at 25 C.

Analysis.--Calculated for C F -N O: 10.9% C; 63.1% F; 21.2% N. Found: 10.8% C; 57.7% F; 23.2% N.

Perfluoro 2-amino-4-oxohexahydro-1,3,5-triazine is characterized by the following important nuclear magnetic shielding values using CFCI as the internal standard:

Peflkga Assignment Approx. Area Ratio +83.1 NF 1 1 +85. 5 CFz-i-NF 3 +ll 9.4 CF 1 l Center of two peaks.

Fluorination of ammeline is effected in a manner similar to that described in Example 1 but without the diluent using 1.5 grams (0.012 mole) of previously thoroughly dried ammeline. After flushing, a stream of 5.5% by volume of fluorine (diluted with nitrogen) is passed through the reactor for 1.5 hours and then 9.1% by volume of fluorine for 4.0 hours at an average rate of about 0.03 mole of fluorine per hour. The cooling liquid is maintained at about --15 C. throughout 5.5 hours. A total of 0.13 mole F is used. The fluorine is then discontinued and the reactor is allowed to warm to room temperature during. 2 hours while the volatile products are flushed through with nitrogen and collected as described above.

The condensate is distilled as described in Example 1 to give about 1.5 grams of the volatile mixture in receiver (B) and about 0.2 ml. of a higher boiling liquid mixture is remaining in the original trap A in contact with ml. of vapor at about 60 mm. Hg at 25 C. This mixture comprises very many components as determined by vapor phase chromatographic analysis as described above. The perfluorinated oxo compounds which are isolated include perfluoro N-aminomethyl-N'-diaminomethylurea, perfluoro 2-amino-4-oxohexahydro-1,3,5-triazine and perfluoro-Z-oxohexahydro-1,3,5-triazine H [FNONFCFzNFSl Fl] In the approximate ratio of 1:2:2. The exact ratios of formation of these products and the total yield are rather variable even in runs which are intended to be identical since it is impracticable to control every possible variable.

Perfluoro 2-ox-ohexahydro-1,3,5-triazine is characterized by the following nuclear magnetic resonance shielding values using CFCl as the internal standard.

Peak Assignment Approx. Area Ratio +69 .3 NF 1 +85 .7 NF 2 +86 .0 CF; 4

Example 3 The procedure of Example 1 is repeated with the internal temperature of the reactor at 0 C. and employing a concentration of 6.9 percent fluorine by volume passed over the mixture at about 0 C. for 1.5 hours. The fluorine concentration is then raised to 11.4% by volume and the stream is continued for 0.7 hour. A total of 0.15 mole of fluorine is used in all. The products of the reaction are collected as described in Example 1 allowing 3 hours for the warming process. They are then separated as described :above.

The liquid residue remaining on distillation amounts to 0.5 ml. in contact with about 50 ml. of vapor at 40 mm. Hg at 25 C. This includes perfluoro-N-aminomethyl-N- diaminomethylurea characterized as described in Example 1 above.

Example 4 A mixture of one gram of ammeline and three grams of sodium fluoride is placed in a 650 ml. rectangular brass reactor which is fitted with a 2" x 10" Monel sintered plate near the bottom, a gas inlet below the sintered plate and an outlet above the sintered plate. After purging the reactor with nitrogen for about one hour, the reactor is cooled externally to about 10 C. (internal temperature about 0 C.) and fluorine is introduced into the gas stream to about 7.2% by volume for one hour and then to 12.5% for 1.5 hours so that 0.16 mole of fluorine are used. The reaction products are condensed directly from the reactor into a liquid air cooled borosilicate glass trap without an intermediate sodium fluoride scrubber. The reactor is then allowed to warm to room temperature and the products collected as above.

Distillation of the products as above gives 3.2 millimoles of a mixture containing bis(difluoramino)difiuoromethane, tris(difiuoramino)fluoromethane, perfluoroguanidine and perfluoroformamidine in the ratio of about 1:1:321 as well as other NF containing products and a residue of 0.5 ml. of liquid in contact with 60 m1. of vapor at 60 mm. Hg at about 25 C. Vapor phase chromatography of this liquid yields perfluoro N-aminomethyl-N-diaminomethylurea, perfluoro 2-oxohexahydro-1,3, 5 triazine and perfluoro 2-amino-4-oxohexahydro-1,3,5- triazine characterized as hereinabove.

Example 5 A dry mixture of two grams of cyameluric acid and six grams of sodium fluoride is charged into a rotatable 1.5

liter, three inch diameter cylindrical copper reactor fitted with gas inlet and outlet. The reactor is rotated at a rate of about 20 r.p.m. at ambient room temperature and flushed with a stream of nitrogen. Fluorine is introduced into the stream to a volume concentration of 9.8% by volume for the first hour, to 15.6% for 1.3 hours and to 22.8% for the final 0.5 hour. A total of 0.3 mole of fluorine is used at an average rate of 0.12 mole/hr. During this process the reaction is exothermic giving inside temperatures of up to 58 C. The fiuorination products are condensed directly from the reactor into a liquid air cooled borosilicate glass trap as in the above examples. Products of the reaction are further recovered from the reactor by purging with nitrogen for 1.5 hours. The combined products are redistilled under reduced pressure to give about 0.5 ml. of high boiling liquid residue (I) in contact with about 50 m1. of vapor at about 30 mm. Hg and more volatile products (II) which collect in the receiver at about 190 C. The latter are warmed to about 78 (solid cO -trichloroethylene bath) and the volatile constituents mainly COF are intermittently expanded into a vapor volume of 370 ml. until the vapor pressure above the liquid residue at 78 is reduced to about 20 mm. Hg. The residue of II, which amounts to about 0.6 ml. at 78 is then separated into its components by vapor phase chromatography employing a 5 meter /2" column composed of 25% by weight of fluoro-silicone fluid (available under the designation FS-1265 from Dow Corning Corp.) on Celite at 80 C. The perfluorinated oxo compounds which are isolated are perfluoro 2-oxohexahydro-1,3,5 triazine and perfluoro 2 amino-4-oxohexahydro-l,3,5-triazine in the approximate ratio of 1:1. Other perfluorinated oxo compounds are present as evidenced by the infrared absorption spectra of minor fractions which show medium to strong absorptions at about 5.4/L.

The high boiling liquid (I) is analyzed and found to contain: 14.1% C; 25.5% N; 58.5% F and corresponds to the empirical formula C N F O It oxidizes a solution of potassium iodide in acetonitrile to liberate about 25.4 meq. of iodine for each gram of sample. The infrared spectrum of this mixture exhibits a strong carbonyl absorption due to the 0 NF()NF linkage at about 5.4 absorptions at 5.75 and 5.9 C=N linkages), absorptions between 7.5 and 8.5;. (CF bonds) and broad absorption between 10 to 11,14 (various NF containing groups). It appears to be a mixture.

The liquid mixture (I) is dissolved in Freon 113 and separated into its various components by vapor phase chromatography employing a column containing fluorosilicane liquid as described above which is heated to C. The sample is injected as the solution.

The perfluorinated oxo-compouds which are isolated as major components are perfluoro 2-amino-4-oxohexahydro-1,3,5-triazine and a higher molecular weight oxocompound in the ratio of about 1:1,. The latter compound which has a vapor pressure of about 20 mm. at 25 C. is perfluoro 2,6-diamino-4-oxohex-ahydro-1,3,5- triazine NF-$F NF: It shows a strong carbonyl absorption in the infrared at 5.4 as well as absorptions in the CF and NF regions. Its nuclear magnetic resonance spectrum shows the major values at about 23.7 (NF +83.0 and +85.2 (NF) and about +115.8 (CF) with other significant peaks at about -25.6 (NF region), and +1163 (CF region) which are presumed to be due to an isomeric compound.

Example 6 This example illustrates a large scale fluorination of ammeline. It will be recognized that in the preparation of these highly energetic compounds on this scale the use of barricades, remote handling and other possible precautions should be taken to prevent possible injuries to personnel or destruction of property.

A stainless steel pressure reactor having inside diameter of 14 inches, and fitted with thermometer well, pressure gauge, a 4 inch magnetic stirrer, gas inlet line ending below the stirrer blade, gas outlet with pressure relief valve and an external cooling coil on the reactor (120 feet length) is charged with four pounds of ammeline, eight pounds of sodium fluoride. and ninety pounds of perfluorocyclic ether C F O (available commercially under the designation FC-75 from the Minnesota Mining and Manufacturing Company). The stirrer runs at about 600 to 700 rpm. The reactor is cooled to about C. and flushed thoroughly with a stream of nitrogen. Fluorine diluted with from to 20% by volume of nitrogen is then introduced at a rate of about 1.6 cubic feet of fluorine per hour for 5.2 hours. Pressure within the reactor is about to p.s.i.g. and the temperature is from about 5 to 15 C. Volatile products of the reaction pass through a glass wool filter and are condensed in the same fluorochemical diluent in a receiver at C. Volatile materials which remain uncondensed are vented. At the end of the reaction, the products remaining in the diluent in the reactor are expelled by gradually raising the temperature to 100 C. while flushing with nitrogen and are collected in the same receiver.

The contents of the receiver are fractionated in a 20 plate column constructed of borosilicate glass. The fraction boiling at about 15 to 20 C. (under atmospheric pressure) comprises perfluoro-N-aminomethyl carbamyl fluoride:

F N-CF NFCOF which is further purified by vapor phase chromatography and/or redistillation. This carbamyl fluoride has strong absorption in the infrared at 5.26;/., due to the carbonyl group, as well as absorption at 7.90, 8.29 and 8.49 due to CF linkage, at 10.61 and 10.79/1. due to NF linkages and other absorptions. Nuclear magnetic resonance determined as above gives the following characteristic shielding values:

4: Assignment Approx. Area Ratio 1 +8 5 OF 1 2 +72 .7 NF 1 3 +97 .5 CF: 2

1 Double triplet. 1 Doublet. a Double doublet.

Example 7 This example illustrates the preparation of a compound of the invention from a 5-membered ring polynitrogen heterocyclic compound. Imidurazole, 3-amino-5-hydroxy- 1,2,4-triazole, is prepared by the method of Pellizzari and Roncagliolo, Gazzeta Chimica Italiana, vol. 31, part I, page 477 (1901).

An anhydrous mixture of 1 g. of imidurazole and 5 g. of sodium fluoride is fluorinated in the apparatus and by the procedure described in Example 4 using fluorine at a concentration of 7.2% by volume for 0.5 hour and of 12.4% for 1.5 hours at average flow rates of 0.024 mole of F per hour and then at 8.1% for 0.5 hour and 12.5% for 1.00 hour at flow rates of 0.09 mole per hour. The total amount of fluorine is 0.18 mole. The temperature within the reactor ranges between 10 and 0 C. The temperature of the reactor is permitted to rise and products are removed in a stream of nitrogen (300 ml. per min.) during 3 hours and condensed as described above. The total products are redistilled as above to a residue of 0.2 ml. in contact with 390 ml. of vapor at about 35 mm. of Hg at --78 C. This residue is separated by vapor phase chromatography on a column 33 by weight of perfluoropolytributylamine (available commercially under the designation FX-45 from the Minnesota Mining and Manufacturing Company) on Celi-te at 25 C. Perfluoro-N- aminomethylcarbamyl fluoride is isolated as one product having characteristics as described above.

What is claimed is:

1. Fluorinated oxo-compound consisting of carbon, nitrogen, fluorine and oxygen having from 2 to 3 carbon atoms separated by nitrogen atoms, at least one of said carbon atoms bonded to two other atoms being doubly bonded to oxygen, and having not more than 5 nitrogen atoms and containing from about 40% to about by weight of fluorine.

2. Perfluoro N-aminomethyl-N'-diaminomethy1urea.

3. Perfluoro 2-amino-4-oxohexahydro-1,3,5-triazine.

4. Perfluoro 2-oxohexahydro-1,3,5-triazine.

5. Perfluoro 2,6-diamino-4-oxohexahydro-1,3,5-triazine.

6. Perfluoro N-aminomethylcarbamyl fluoride.

References Cited UNITED STATES PATENTS 1/1966 Davis et al. 260-2476 10/1966 Sheehan et a1. 2605S3 OTHER REFERENCES HENRY R. JILES, Primary Examiner.

J. M. FORD, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,410,853 November 12 1968 Robert J Koshar It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, lines 52 and 53, the right-hand formula should appear as shown below:

Column 3, line 11 the formula should appear as shown below:

F2N-CFZ?'FN CO-NF CF 2 Column 4, line 6, the formula should appear as shown below:

Column 6, line 37, "excess of about 50 C. for best" should read excess of about 50 C. For best Column 8, line 47 NF" should read =NF Column 9, line 24, NF" should read =NF Column 10, line 47, C=N- linkages)" should read (=C=N- linkages) Signed and sealed this 10th day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

2. PERFLUORO N-AMINOMETHYL-N''-DIAMINOMETHYLUREA.
 4. PERFLUORO 2-OXOHEXAHYDRO-1,3,5-TRIAZINE. 